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  • Drivers for Basic 2-Way Speaker Build - Am I on the Right Track?

    Hello All,

    I have read just enough to be dangerous concerning speakers & such. I'm not trying to build an audiophile's wet dream, just a pair of basic 2-way speakers for my garage that will meet the following criteria:

    * 4-ohm. I'll be driving them from a car stereo head unit, so looking at a realistic 15-20W RMS maximum. Need good efficiency due to low power amplifier.

    * Simple, compact box design. I'm a capable woodworker but don't want to spend the next year on this and have limited space in my garage. Need to keep boxes under 1 ft^3.

    * Good clarity and definition with punchy bass and as much low bass extension as I can get. I don't expect to shake stuff off the walls with these, just want them to be accurate and easy to listen to. Again, not looking to blow anyone's minds with sound quality but want them to sound good enough to justify the $ and time I'll put into building them. The drivers I've chosen are fine with me as far as cost but of course, if I can get better results for less $ then I'm VERY open to suggestions.

    So now that you know the parameters, here are two options I've chosen based on what's available here at Parts Express:

    Option 1:
    (Part # 292-570) Visaton W200S-4 8" Woofer with Treated Paper Cone 4 Ohm
    +
    (Part # 292-554) Visaton DT94-4 0.8" Polycarbonate Dome Tweeter 4 Ohm

    Crossed over at either 2500 or 3000 using the Dayton Audio crossovers.

    The woofer looks like it has great bass characteristics and a relatively smooth response curve. I should be able to get pretty good bass out of this in a modestly sized sealed box. My concern is the sensitivity being only 86db from the woofer. This may not allow me to get the most out of the low power amplifier I'll be using and the tweeter is significantly more sensitive so might overpower the woofer?

    Option 2:
    (Part # 295-567) Dayton Audio RS225P-4A 8" Reference Paper Woofer 4 Ohm
    +
    (Part # 275-141) Dayton Audio RST28F-4 1-1/8" Reference Series Fabric Dome Tweeter 4 Ohm

    Crossed over at 2000 or 2500 using Dayton crossover.

    Doesn't look like I'll get as good of bass extension from this setup but the SPLs of the speakers are better matched and I'm guessing this tweeter is just a better all around tweeter than the Visaton. I can build a vented box that will get decent low bass and still stay within my size constraints though I'm really curious what it would sound like in a sealed box (I tend to like the sound of sealed boxes better.) I can always build both and experiment...

    Okay - am I thinking about this setup the right way? Are these two options good choices? Which crossover points would you choose? Would you recommend something different?

    Thanks for any thoughts/input!

  • #2
    If you want to use the Visaton, I would go to their website and build a project they designed. That tweeter will not work with that woofer, In my opinion.

    Comment


    • #3
      Thanks howard. I poked around at Visaton's site and didn't see any projects that use that specific speaker. In fact, didn't see any that use 4-ohm speakers at all. I suppose I could've missed it...

      Can you elaborate why you think that tweeter won't work - SPL/efficiency mismatch or something else? Any suggestions for a different tweeter?

      Any thoughts about option 2?

      Thanks again.

      Comment


      • #4
        Look at the Alto 1. To me, that would be the best I could find. If you look at the frequency response graphs I don't think that the two drivers will work together. Maybe the Dayton pair would work but not with a pre made crossover.
        Last edited by howard; 10-09-2018, 11:06 PM. Reason: spelling

        Comment


        • #5
          Thanks again Howard. I appreciate your sharing your experience with me as I try to learn this stuff. If you have any suggested reading material or links you can share that would help me be better at assessing these things for myself, I'd appreciate it.

          In the meanwhile, if you don't mind me pestering you - The frequency ranges of the Visaton speakers seem to overlap quite nicely but the tweeter is obviously much "louder" than the woofer. Is that why you feel they wouldn't work? As I mentioned above, I was afraid the relative efficiencies/SPL ratings of the two might not be compatible and the tweeter would overpower the woofer. Is that it, or is there something else I'm not seeing? I'm just real curious what it is you're seeing that makes you say they won't work.

          The Dayton speakers seem to be more closely matched with good overlap of their frequency ranges. What is it about a pre made crossover that makes them unsuitable?

          Comment


          • #6
            I did a little more poking around and it appears that the Dayton crossovers with the switchable 4/8 ohm setting only change the setting for the low pass portion. It looks like the high pass section doesn't change and is still designed for an 8 ohm tweeter.

            I also did a bit more reading and it seems that as long as I'm using a 4-ohm woofer an 8-ohm tweeter won't present much more load to the amp so the overall speaker impedance will still be close to 4 ohms.

            If I'm understanding all this correctly, then it seems this tweeter would be a better match for the Dayton woofer with a 12db crossover point at either 2000 or 2500 hz.

            (Part # 275-070) Dayton Audio DC28F-8 1-1/8" Silk Dome Tweeter.

            Comment


            • #7
              Originally posted by WillB View Post
              Thanks again Howard. I appreciate your sharing your experience with me as I try to learn this stuff. If you have any suggested reading material or links you can share that would help me be better at assessing these things for myself, I'd appreciate it.

              In the meanwhile, if you don't mind me pestering you - The frequency ranges of the Visaton speakers seem to overlap quite nicely but the tweeter is obviously much "louder" than the woofer. Is that why you feel they wouldn't work? As I mentioned above, I was afraid the relative efficiencies/SPL ratings of the two might not be compatible and the tweeter would overpower the woofer. Is that it, or is there something else I'm not seeing? I'm just real curious what it is you're seeing that makes you say they won't work.

              The Dayton speakers seem to be more closely matched with good overlap of their frequency ranges. What is it about a pre made crossover that makes them unsuitable?
              You will get many comments on the issue of pre-made crossovers, the main one being: please don't do it or you will be disappointed. Unless of course the pre-made crossover has been designed for the drivers: Visaton, for example, sells custom and assembled crossovers for its kits, at least in Australia.

              I'll let others with infinitely more knowledge and experience explain why, but the gist of it is that they don't and can't work properly because drivers don't have 'textbook' responses. To give just two reasons, they don't provide "Baffle Step Compensation" or an "L-Pad' to match the woofer and tweeter outputs.

              I was all set to use pre-made crossovers until I found and joined this forum and understood a bit about how these things work; I then built proven designs with custom crossovers designed by people who know their stuff and am very happy.

              Apart from TM speakers with a 4 ohm woofer and 4 ohm tweeter - and remember, this is always a nominal figure as the real resistance will vary with frequency- a typical MTM with 8 ohm woofers connected in parallel and a 4 ohm tweeter, will probably give a '4 ohm' speaker (although in practice, more like 6 ohms).

              If you want a speaker with enough output for your garage, you might consider an MTM rather than a TM. There are many highly regarded projects at different price levels: do you have a budget in mind? Depending on the drivers, the MTM cabinet size could be OK.

              Another thing to think about is the efficiency of the speaker: there are many efficient 8 ohm drivers/speakers, so maybe look at projects with an efficiency of at least 88dB to match with your amp?

              Hope this helps


              Geoff
              Last edited by Geoff Millar; 10-10-2018, 06:10 AM.

              Comment


              • #8
                Option one:
                Scrap the premade xover idea. Get a tweeter that will play a lot lower to about 1.8kHz. That dinky little booger you chose will not have the lower treble extension to meet in the middle with an 8" woofer. You'd honestly need a midrange to make the 8" meet that small tweeter; ie- a 3-way. In general, a 1.125" tweeter is the norm for this kind of combo, and in general, the xover should be between 1.5k-1.8k for the best results in off-axis and lobing of the system. Some may tell you a waveguide is also required to make the tweeter and 8" woofer blend better. While this is not the only solution, it is a viable one.

                Option two:
                Scrap the premade xover idea. Get a tweeter that will play a lot lower to about 1.8kHz. This tweeter you chose is a good option for this kind of design, and the xover could likely even be lower with this combo, say 1.2k-1.8k, so your flexibility is much better. There is no BOM for this particular set of drivers yet, TMK, so you'd be on your on here as well.

                More notes:
                Do not use a xover calculator, as you'll get as the premade ones would yield.
                Learn what BSC is.
                Being brand dependent is not required.

                ...and there is a lot more reading in your future if you want the optimal conclusion out of your endeavor.

                Later,
                Wolf
                "Wolf, you shall now be known as "King of the Zip ties." -Pete00t
                "Wolf and speakers equivalent to Picasso and 'Blue'" -dantheman
                "He is a true ambassador for this forum and speaker DIY in general." -Ed Froste
                "We're all in this together, so keep your stick on the ice!" - Red Green aka Steve Smith

                *InDIYana event website*

                Photobucket pages:
                http://photobucket.com/Wolf-Speakers_and_more

                My blog/writeups/thoughts here at PE:
                http://techtalk.parts-express.com/blog.php?u=4102

                Comment


                • #9
                  The Fs of the 3/4" tweeter is around 2kHz (so... ROUGHLY shouldn't be crossed below about 4k - and that's at least an octave too high for an 8" woofer, generally speaking).
                  The Dayton tweeter is hard to beat (although you probably COULD get adequate results from something cheaper).
                  Like Wolf says, no reason not to mix brands. The RST tweeter will work w/either the Dayton woofer OR the Visaton.

                  A GREAT book to read is "SpeakerBuilding 201" by Ray Alden (a good reference to have around as well).
                  If there were 100 things you'd have to know to design a "good" system, right now you're aware of probably < 10% of them.

                  You ALMOST have to vent the box to get a "full range" system for music (which means lower 40s). You CAN fit the RS225P-4 into 1.0cf w/a 3"id x 10" long port that will reach 40Hz. In GENeral, a closed box will have about one-half the interior volume, but you lose nearly an octave off the bass end.
                  You can model bass response in a box using WinISD, which is free at linearteam.org .

                  You COULD just build the "Dayton IIIs". Then you'd have some pretty good listening to tunes while you spend the next 4 yrs of your life learning all this stuff (so you could design your own).

                  Comment


                  • #10
                    Hi WillB - the perennial advice is "build a proven design" as your first project.
                    This hobby takes a lot of time to understand the variables and tradeoffs.
                    If you can accept a 6 inch woofer and a smaller box, this project should be outstanding for your needs.

                    Want a second or third opinion about your speaker cabinet design or other audio related problem? Post your question or comment on the Technical Discussion Board. Hundreds of technicians, engineers, and hobbyists, nationwide read and discuss electronics related questions each week. We welcome your participation

                    I think I hear a difference - wow, it's amazing!" Ethan Winer: audio myths
                    "As God is my witness I'll never be without a good pair of speakers!" Scarlett O'Hara

                    High value, high quality RS150/TB28-537SH bookshelf - TARGAS NLA!
                    SB13/Vifa BC25SC06 MTM DCR Galeons-SB13-MTM
                    My Voxel min sub Yet-another-Voxel-build

                    Tangband W6-sub

                    Comment


                    • #11
                      Are you looking for a new hobby or just a pair of garage speakers? Buying fairly expensive drivers and combining them with little knowledge is the wrong path, IMHO.

                      Both the above projects are great choices, I'll float this one and you can poopoo it if you wish. Certainly "good enough" for the garage. No offense to JR, I link his designs all the time. He has other GRS based designs you might want to look at. This one fits in a PE mdf flat pack, you have to make the holes.

                      Cabrini Redux - Techtalk Speaker Building, Audio, Video Discussion Forum

                      Comment


                      • #12
                        Wow, thanks for all the responses!

                        I certainly wouldn't mind building a proven project if there's one that meets my needs. I'm a big fan of letting other, smarter people figure stuff out and then building on their success... LOL. I don't think diving deep into the speaker designing/building hobby is in my future. Was just hoping I could build something that would meet my needs better and cost less than anything I could find in the stores around here. I have lots of other hobbies that take up my time, thus the reason for needing some good tunes in my garage while I restore my old cars...

                        I'm currently listening to an old pair of Alpine 6.5" 2-way car door speakers mounted in some cheap pre-made boxes. The sound is less than impressive, was hoping to be able to really improve on that with a little effort.

                        I looked at the projects linked by Chris Roemer, donradick, and djg and they all look pretty cool and obviously produce nice results. A big problem with them is the rear-firing ports. Since this is my garage, I'm just going to put them up on shelves in the corners, aimed in towards the middle. I don't think that's the optimum placement for something with a rear-firing port. Need a front-firing port or sealed enclosure. I might try building those Dayton IIIs for my living room though! They would blow away my old Altec Lansings that I've had for 25 years...

                        Given the puny amplifier I really think I need to stick to something that doesn't present more load than a typical 4-ohm car speaker would. I've tried using 8-ohm "home" speakers with car amps before and the loss of output is really noticeable, and that was with an old school (from the '80s) Alpine 40W amplifier (true 40W RMS). If the amp in this car head unit puts out more than 20W RMS at low distortion numbers I'd be shocked.

                        So, y'all have given me lots to think about, thank you! I'll go searching for proven projects that meet my needs. If you have any other suggestions for a particular project, especially one with a low overall impedance I'd really appreciate it!

                        Some random further questions & thoughts -

                        Should the Parts Express marketing info about various speakers be taken with a huge grain of salt? For example, both of the woofers I'm looking at were chosen specifically for their extended high frequency response compared to other 8" woofers. Parts Express even says the Visaton can be crossed over as high as 3Khz but it seems no one here would actually do that.


                        Crossover design - Reading about it I see that people are taking measurements from the speakers as they are installed in the intended enclosures to design the appropriate crossover. Unfortunately I have no way to do that. I don't have any such testing equipment and can't see myself investing in it so I guess this means I'm either going to have to use pre-made crossovers or stick to only proven designs.

                        Thanks again for all your input!

                        Comment


                        • #13
                          There's absolutely nothing wrong, and everything right, with using existing and proven designs, especially since speaker building isn't your hobby/obsession. After all, you will get speakers you're happy with and not have wasted money building something which you don't like!

                          I've only built four pairs of DIY speakers, all other peoples' designs, each made for a particular purpose and as I said above, I'm very happy. I'm in the process of building a fifth, again a design from someone on this Forum who knows their stuff. With the exception of the Tritrix, they all use different brands of woofers and tweeters in the same cabinet, no problem at all - in fact this is probably the most common configuration.

                          In Australia, Visaton drivers are very costly, so I've used Dayton DC and RS, Peerless, VIFA and Morel. Happy with all of them.

                          As for ports, my vague understanding is that they can go on the front or back, provided the front panel has enough room for the port to fit, but this will vary with the design. Certainly, the Classix II and 2.5 can be made that way, but do check with the designer first, they will be happy to help.

                          In terms of projects, there are many which will fit within your 1 cubic foot cabinet size, but you might also consider a design which has a simple crossover, as building one can be intimidating at first; at least it was for me.

                          Geoff

                          Comment


                          • #14
                            The design I linked is sealed. No port. You don't need 6 feet of clearance for a port. A few inches will do. How close to the opposite cab wall is the inside end of the port?

                            Paul Carmody's S2000 MTM is 4 ohm, 91db sensitivity, and as everyone always says, has amazing bass output considering. DIYsoundgroup.

                            Ooh, look at this, 8", sealed, cheap.

                            All GRS small 3-way - Techtalk Speaker Building, Audio, Video Discussion Forum

                            Comment


                            • #15
                              Just to add a short bit not mentioned, unless I missed it.

                              Based on your preference of bass sound, and the size of the box, you could use a passive radiator instead of a port. This'll eliminate having to deal with port tube construction and everything else related to ports. The PR can have weight in grams added (bolt + washers) to fine tune it against a woofer, thereby tweaking the final box tuning to get it where you want it, or very close.

                              IIRC a standard for PR is roughly having either 2 PR the same size as the woofer they're dancing with, or a PR larger than (with more xmax than) the primary woofer, eliminating the ability to ever damage the PR if the woofer is driven (but held at) its limits for rocking the garage.

                              Just another 2c. Experts will chime in if I misspoke, which is possible since its a crusty memory I haven't had to "think" about for several years.

                              That'll change soon though as I'll finally be using a DATS kit to find my actual tuning and have hardware ready to add mass to the PR if it's way off my mark.
                              Feel free to rip my assumptions apart when wrong, or fix if close.

                              Passive Radiators:
                              All PR(s) Vd must at-least double all woofer(s) Vd. Calc = Sd x Xmax to get Vd for all PR(s) and all woofer(s). If all PR(s) Vd at-least double all woofer(s) Vd they'll work.
                              For woofer(s) with large Xmax vs Sd, all PR(s) with Xmax at-least double all woofer(s) Xmax will work.
                              A PR max weight is said to be its Mms x3

                              PR Systems - tight focus with key parameters.
                              PR Speaker Design - thorough coverage.

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